KR101538243B1 - Method for improving handleability of calcium carbonate containing materials - Google Patents

Abstract

The present invention relates to calcium carbonate containing materials having increased bulk density in equivalent or improved fluidity, and methods of making such materials. The process of the present invention comprises contacting a calcium carbonate containing miner powder with a solution or emulsion or dispersion of a binder.

Description

METHOD FOR IMPROVING HANDLABILITY OF CALCIUM CARBONATE CONTAINING MATERIALS [0002]

The present invention relates to a calcium carbonate-containing material, and more particularly to a calcium carbonate-containing mineral powder having an increased bulk density, and a process for producing the same.

Inorganic materials are used in the manufacture of paper, paint, plastics and similar products, and it is well known to incorporate quantities of inorganic materials into fiber webs, paints or plastics to improve the quality of the resulting products. Of those materials, substances that are found to increase their acceptance as fillers, particularly in such applications, are calcium carbonate containing minerals. This type of material is generally produced by dry grinding or wet grinding and drying, which can be initially treated with a pre-rounding step to remove certain impurities, for example, for the purpose of improving brightness in the final product. However, such dry powders have the disadvantage that they have a low bulk density which makes them difficult to handle. For example, a calcium carbonate containing mineral powder product is usually sold by the manufacturer as a final finely divided low bulk density powder, and the powder has a limited storage capacity. Moreover, such products are typically packaged or shipped in bulk, but due to their low bulk density, typically only 25 to 35 tonnes of powder can be loaded into the 40 m ³ orbital car.

In the past, densification equipment such as a bricketting machine or

Efforts have been made to increase the bulk density of such powders using a pelletizer. However, these efforts have proved unacceptable for several reasons. When the bulk density of such powders is mechanically increased by the pressure, the flow properties of such powders deteriorate. A larger energy input is needed to load the product into the tank or container or to empty such tank or container. In addition, water-dependent pelletizing equipment as a binder has been found to require the addition of large quantities of water (approximately 15 to 25% by weight of calcium carbonate) in order for acceptable pellets to be formed. This water increases the shipping cost of the product or increases the manufacturing cost, because it has to be evaporated before shipment. Pelletizing equipment relying on other binder than water has also been found to result in pelletized products that require large amounts of binder and are difficult to pellet and remain in water after drying.

US 4,561,597 discloses a process for reducing the time to wet wet kaolin clay powder with water and increasing its bulk density, comprising the steps of dry ball milling said powder using a specific energy input, And removing the larger particles that have not been removed.

WO 2006/008657 relates to a process for preparing self-bonding pigment particles, which comprises forming an aqueous suspension of an inorganic substance and introducing it into a mill, forming an aqueous solution or suspension of the one or more binders or an aqueous emulsion Introducing it into a pulverizer, and pulverizing the aqueous suspension in such a manner as to obtain an aqueous suspension of pigment particles self-binding together with an aqueous solution or suspension or emulsion.

Processes for the preparation of dry pigment granules are described in WO 01/00712. The method comprises mixing the organic polymer pigment, optionally an inorganic pigment, a binder and water to form a dispersion, and spray drying the dispersion. The binder binds the particles into an agglomerate, which is easier to handle in powder form without the problem of dusting.

WO 01/00713 relates to a process for preparing plastic polymeric pigments wherein the aqueous dispersion of plastic polymeric pigments is dried. The resulting plastic pigment particles are bound together by electrostatic force to form aggregates.

There remains a need in the art for a method of improving the bulk handling properties of calcium carbonate-containing mineral powders.

Therefore, it is an object of the present invention to provide a method for producing calcium carbonate-containing mineral powder having improved bulk handling characteristics when the powder is stored, loaded, unloaded and shipped, for example. Another object of the present invention is to provide a calcium carbonate-containing mineral powder which requires a lower storage capacity than conventional calcium carbonate-containing mineral powder and thus permits reduction of the storage cost of such powder. It is desirable to provide a method for producing a calcium carbonate-containing mineral powder having an increased bulk density in equivalent or improved fluidity compared to conventional calcium carbonate containing mineral powder. It is also desirable to provide a calcium carbonate containing mineral powder wherein a lower energy input is needed to load the powder into the container or unload the powder from the container. In addition, it is desirable to provide calcium carbonate-containing mineral powder with increased bulk density, wherein all other characteristics and / or properties of conventional calcium carbonate-containing particles are at least maintained or even improved. It is also desirable to provide a calcium carbonate-containing mineral powder having an increased bulk density that can be easily suspended in water.

The foregoing and other objects are achieved by a process for producing a calcium carbonate-containing composite particle comprising the steps of:

(a) providing at least one calcium carbonate-containing mineral powder,

(b) preparing one or more solutions or emulsions or dispersions of one or more binders, and

(c) contacting at least one calcium carbonate-containing mineral powder of step (a) in an amount to form a solid calcium carbonate-containing composite particle with at least one solution or emulsion or dispersion of the binder of step (b)

And the dried calcium carbonate-containing composite particles have an equivalent or improved (relative to the calcium carbonate containing minerals powder provided in step (a)) at a total surface moisture content of less than 0.5% by weight based on the total weight of the composite particles And has an increased bulk density at reduced flowability.

According to another embodiment of the present invention, the calcium carbonate-containing composite particles are provided to have an increased bulk density in equivalent or improved fluidity, which can be obtained by the process as described above.

According to another embodiment of the present invention, the binder is used to increase the bulk density of the calcium carbonate-containing mineral powder in equivalent or improved fluidity.

According to another embodiment of the present invention, the calcium carbonate-containing composite particles of the present invention are used in paper applications, in paints or in plastics.

Advantageous embodiments of the invention are defined in the corresponding dependent claims.

According to one embodiment, the bulk density of the dried calcium carbonate-containing particles is compared with the calcium carbonate-containing mineral powder provided in step (a) at a total surface moisture content of less than 0.5% by weight based on the total weight of the composite particles By 5 to 80%, preferably by 8 to 60%, more preferably by 10 to 50%.

According to one embodiment, the at least one calcium carbonate containing mineral powder provided in step (a) is selected from the group consisting of GCC and PCC, and mixtures thereof. According to another embodiment, the powder particles of the at least one calcium carbonate-containing mineral powder provided in step (a) have a weight of from 0.1 to 100 mu m, from 0.3 to 50 mu m, or from 0.4 to 10 mu m, preferably from 0.5 to 5.0 mu m Particle size d ₅₀ . According to another embodiment, the one or more calcium carbonate-containing mineral powders provided in step (a) comprise less than 10 wt%, less than 5 wt%, less than 2 wt%, less than 1 wt% Preferably less than 0.5% by weight, more preferably less than 0.2% by weight and most preferably less than 0.1% by weight.

According to one embodiment, the at least one binder provided in step (b) is selected from the group consisting of copolymers of acrylonitrile, butadiene, acrylate, butyl acrylate, styrene, styrene-butadiene and acrylic acid esters, , And preferably the at least one binder provided in step (b) is selected from the group comprising styrene-acrylate copolymers and styrene-butadiene copolymers, and mixtures thereof. According to another embodiment, the amount of the at least one binder provided in step (b) is less than 10 wt%, preferably less than 7 wt%, more preferably less than 5 wt%, based on the total weight of the calcium carbonate containing minerals powder %, Most preferably 0.1 to 4 wt%.

According to one embodiment, the at least one calcium carbonate-containing mineral powder provided in step (a) is brought into contact with at least one solution or emulsion or dispersion of one or more cationic polymers before, during or after step (c). According to another embodiment, the at least one cationic polymer is selected from linear polyethyleneimines, or polyamine amide epichlorohydrin or mixtures thereof. According to another embodiment, the amount of the at least one cationic polymer is less than 1.0% by weight, preferably less than 0.8% by weight, more preferably less than 0.5% by weight, most preferably less than 0.5% by weight based on the total weight of the calcium carbonate- Is less than 0.2% by weight.

According to one embodiment, process step (c) is carried out at a temperature of from 5 캜 to 140 캜, preferably from 10 to 110 캜, most preferably from 20 캜 to 105 캜, or from 40 to 105 캜.

According to one embodiment, the process of the present invention comprises a further step (d) wherein the calcium carbonate-containing multiparticulates obtained in step (c) are dried, preferably 1 Less than 0.8 wt.%, Less than 0.5 wt.%, Preferably less than 0.2 wt.%, Most preferably less than 0.1 wt.% Of the total surface moisture content.

According to another embodiment, the process of the present invention comprises an additional step (e) wherein the dried calcium carbonate-containing multiparticulates obtained in step (d) are desalted to remove undesired larger particles, preferably 100 And are sorted and / or pneumatically sorted to remove particles that are greater than, preferably greater than 50 microns, and more preferably greater than 20 microns.

According to one embodiment, process step (c) is carried out in a grinding apparatus, preferably in a ball mill, preferably agglomerates and / or aggregates formed during process step (c) In combination with a cyclone device that recirculates into the inlet. According to another embodiment, the calcium carbonate-containing composite particles formed during process step (c) are divided into smaller particles.

According to one embodiment, the slurry is prepared from the calcium carbonate-containing multiparticulates obtained in process step (c) by the addition of water and optionally a dispersant. According to yet other embodiments, the dispersing agent is sodium polyacrylate having a weight average molecular weight M _w of 2000 to 15000 g / mol, preferably 3000 to 7000 g / mol, and most preferably from 3500 to 6000 g / mol. According to another embodiment, the slurry has a solids content of 10 to 82 wt%, preferably 50 to 81 wt%, more preferably 60 to 70 wt% or 70 to 78 wt%, based on the total weight of the slurry .

The term "binder" as used herein is a compound conventionally used to bind two or more different materials together as a mixture. However, in the process of the present invention, the binder has the effect of improving the bulk density of the calcium carbonate-containing mineral powder in an effect other than aggregation, i.e., equivalent or improved flowability.

"Bulk density" in the sense of the present invention is defined as the characteristic of powder, granules and other "divided" solids and the mass of the majority of the material divided by the total volume occupied by them. The total volume includes particle volume, interparticle void volume, and internal pore volume. The bulk density of the present invention can be measured by the Powder Rheometer System FT4 (Freeman Technology Ltd., England) and is specified in kg / dm ³ .

For the purpose of the present invention, the term "calcium carbonate-containing mineral powder" includes "ground calcium carbonate" (GCC) and / or "precipitated calcium carbonate" (PCC). The at least one calcium carbonate-containing mineral powder has a total surface moisture content of less than 10% by weight based on the total weight of the mineral powder.

The term "dried" calcium carbonate containing multiparticulates means a calcium carbonate containing multiparticulate having a total surface moisture content of less than 0.5% by weight, preferably less than 0.2% by weight, based on the total weight of the multiparticulates.

As used herein, the term "energy comsumption" is a measure of the energy required to transport one thousand metric tons of powder or particles. Throughout the present invention, energy consumption is used as a measure for the "flow properties" of bulk solids, the smaller the energy consumption, the better the fluidity of the bulk solids. The energy "consumption" of the present invention can be measured using a Powder Rheometer System FT4 (Freeman Technology Ltd., UK) and is specified in kJ / t.

In the sense of the present invention, "fluidity" is a characteristic of powders, granules and other "divided" solids and is defined by the energy consumption in powder movement of the powder product. The fluidity of the present invention can be measured by the Powder Rheometer System FT4 (Freeman Technology Ltd., UK) and is specified in kJ / t.

"Grinded calcium carbonate (GCC)" in the sense of the present invention is obtained from a natural source including marble, chalk or limestone and can be obtained by wet and / or dry grinding, wetting and / or after screening and / For example by centrifugation or cyclone.

Throughout this document, the "particle size" of the calcium carbonate product is accounted for by the distribution of particle sizes. The value d _x represents the diameter relative to the x weight percent of the particles having a diameter less than d _x . This d ₂₀ Value means that 20 wt% of all particles are of smaller particle size, and the value of d ₇₅ means that 75 wt% of all particles are of smaller particle size. Thus, therefore, d ₅₀ The value is the weighted median particle size, i.e. 50 wt% of all particles are larger or smaller than such particle size. For purposes of the present invention, the particle size is specified as the weighted median particle size d ₅₀ , unless otherwise indicated. A Sedigraph 5100 instrument (Micromeritics, USA) can be used to measure the weighted average particle size d ₅₀ value for particles having a d ₅₀ of greater than 0.5 μm.

In the sense of the present invention, "precipitated calcium carbonate (PCC)" is generally obtained by precipitating by carrying out the reaction of carbon dioxide with limestone in an aqueous environment or by precipitating calcium and carbonate sources such as sodium carbonate and calcium chloride in water.

The term "powder " as used in the present invention includes solid mineral powder of at least 90% by weight, based on the total weight of the powder, of inorganic mineral material, wherein the powder particles have a particle size of less than 100 m, preferably less than 50 m, and more preferably less than 10 ㎛, most preferably of 5.0 to 0.5 ㎛ ㎛ d ₅₀ value.

For purposes of the present invention, a "slurry" includes an insoluble solid and water, optionally containing further additives, usually containing a large amount of solids and thus having a higher viscosity and generally a higher density than the liquid in which it is formed .

The term "solid" calcium carbonate-containing composite particle in the sense of the present invention means a composite particle containing calcium carbonate having a solids content of at least 90% by weight, based on the total weight of the composite particle.

For the purpose of the present invention, the term "total surface moisture content" refers to the surface of a composite particle containing calcium carbonate-containing minerals and / or calcium carbonate, and a composite particle containing calcium carbonate-containing minerals powder and / Means the amount of water absorbed in the pores in the particle. The water weight% of the present invention is measured according to the Coulometric Karl Fischer measurement method wherein the mineral powder and / or composite particles are heated to 220 ° C and discharged as a vapor using a nitrogen gas stream (100 ml / min) The water content is measured in a Coulometric Karl Fischer unit.

The process of the present invention for producing calcium carbonate-containing multiparticulates with increased bulk density in equivalent or improved fluidity comprises the steps of (a) providing one or more calcium carbonate containing mineral powders, (b) providing one or more solutions of one or more binders (C) mixing one or more calcium carbonate-containing mineral powders of step (a) with one or more solutions or emulsions or dispersions of the binder of step (b) in an amount to form solid calcium carbonate-containing multiparticulates Wherein the dried calcium carbonate composite particles have a total surface water content of less than 0.5% by weight, based on the total weight of the composite particles, of the calcium carbonate-containing mineral powder provided in step (a) Have an increased bulk density in equivalent or improved fluidity as compared.

The inventors have surprisingly found that the bulk density of calcium carbonate containing minerals powders can be improved by contacting the dry calcium carbonate containing minerals powders with a solution or emulsion or dispersion of binder in an equivalent or improved flowability.

Without wishing to be bound by any theory, it is believed that the binder modifies the particle formation of the calcium carbonate containing minerals powder and acts counter to the set of powder particles. This results in an improvement in the packing and flow properties of the calcium carbonate-containing mineral powder. However, the characteristics of the calcium carbonate-containing powder are not impaired to any substantial extent by the process of the present invention, i.e. all of the desired material properties, such as opacity, bonding properties, etc., remain substantially undamaged or even further improved .

Process step (a): one or more calcium carbonate-containing mineral powders

One or more calcium carbonate containing mineral powders that may be used in the process of the present invention may be calcium carbonate, for example, calcium carbonate present in the form of ground calcium carbonate (GCC) or precipitated calcium carbonate (PCC) .

Natural ground calcium carbonate (GCC) may be characterized, for example, by one or more of marble, limestone, chalk and / or dolomite. According to one embodiment of the present invention, the GCC is obtained by dry milling. According to another embodiment of the present invention, the GCC is obtained by wet grinding and subsequent drying.

Generally, the grinding step is carried out in the presence of any conventional grinding apparatus, for example, a secondary body such as a ball mill, a rod mill, a vibrating mill, a crusher, a centrifugal impact mill, a vertical bead mill, To be primarily produced as a result of secondary body impact at one or more of the following: at least one of a mill, a hammer mill, a pulveriser, a shredder, a de-clumper, a knife cutter, or other equipment known to those skilled in the art Under one condition. When the calcium carbonate-containing mineral powder comprises a wet-milled calcium carbonate-containing mineral material, the milling step is carried out under conditions such that autogenous milling occurs and / or occurs by horizontal ball milling and / or other such processes known to those skilled in the art . The wet treated pulverized calcium carbonate-containing mineral material thus obtained can be washed before drying and can be dehydrated by well known processes, for example, by agglomeration, filtration or forced evaporation. Subsequent drying steps may be performed in a single step such as spray drying, or may be carried out in at least two stages. Further, such mineral materials are generally subjected to a beneficiation step (e.g., float, bleaching or magnetic separation step) to remove impurities.

The precipitated calcium carbonate (PCC) may, for example, be characterized by one or more of aragonite, bartterite and / or calcite-type mineralogical crystalline forms. Aragonite is generally present in the form of needles, while the baterite type is in the hexagonal system. Calcite can form triangular, prismatic, spherical, and rhombohedral forms. The PCC can be prepared in a different way, for example by precipitation with carbon dioxide, soda lime process, or by the Solvay process, which is a by-product of ammonia production of PCC. The resulting PCC slurry can be mechanically dehydrated and dried.

According to one embodiment of the present invention, the at least one calcium carbonate-containing mineral powder provided in step (a) is selected from the group consisting of GCC and PCC, and mixtures thereof.

According to a preferred embodiment of the present invention, the at least one calcium carbonate-containing mineral powder comprises ground calcium carbonate (GCC).

In addition to calcium carbonate, the calcium carbonate-containing mineral powder may contain further metal oxides such as titanium dioxide and / or aluminum trioxide, metal hydroxides such as aluminum trihydroxide, metal salts such as sulfates, silicates such as talc and / or kaolin clay and / Mica, carbonates such as magnesium carbonate, and / or gypsum, satin white, and mixtures thereof.

According to one embodiment of the present invention, the amount of calcium carbonate in the calcium carbonate-containing mineral powder is at least 90% by weight, for example at least 95% by weight, preferably at least 99% by weight, based on the total weight of the calcium carbonate- , More preferably at least 99.5 wt%, or most preferably at least 99.8 wt%.

The total surface moisture content of the at least one calcium carbonate-containing mineral powder is less than 10% by weight based on the total weight of the mineral powder. According to one embodiment of the present invention, the moisture content of the one or more calcium carbonate containing mineral powders is less than 10% by weight, less than 5% by weight, less than 2% by weight, less than 1% by weight based on the total weight of the mineral powder Less than 0.5% by weight, more preferably less than 0.2% by weight, most preferably less than 0.1% by weight.

In one preferred embodiment, the one or more calcium carbonate-containing mineral powders are present in a moisture atmosphere having a relative humidity of 50%, even after 48 hours of exposure at 23 < 0 > C, %, Preferably 0.02 wt.% To 0.9 wt.%, More preferably 0.03 wt.% To 0.09 wt.% Of the total surface moisture content.

The powder particles of the calcium carbonate-containing mineral powder may have a d ₅₀ value of 0.1 to 100 μm, 0.3 to 50 μm, or 0.4 to 10 μm. Preferably, the powder of the calcium carbonate-containing mineral powder has a d ₅₀ value of about 0.5 to 5.0 μm.

Process step (b): one or more solutions or emulsions or dispersions of one or more binders

In step (b) of the process of the present invention, one or more solutions or emulsions or dispersions of one or more binders are prepared. Suitable binders include, for example, binders of natural origin such as starches, proteins such as casein, cellulose and cellulose derivatives such as ethylhydroxyethylcellulose (EHEC) and / or carboxymethylcellulose (CMC) For example, polyvinyl acetate (PVA), acrylic binders such as acrylic ester binders and / or acrylonitrile binders and / or styrene-acrylate binders, styrene binders, styrene-butadiene binders and butadiene binders, .

According to a preferred embodiment of the invention, the at least one binder is a synthetic binder, for example a polymer binder.

According to another embodiment of the present invention, the one or more binders are selected from the group consisting of copolymers of acrylonitrile, butadiene, acrylate, butyl acrylate, styrene, styrene-butadiene, and acrylic esters, Polymeric binder. Examples of suitable polymeric binders include poly (styrene-co-butadiene), polyurethane latex, polyester latex, poly (n-butyl acrylate), poly (n-butyl methacrylate) ), copolymers of n-butyl acrylate and ethyl acrylate, or copolymers of vinyl acetate and n-butyl acrylate.

According to an embodiment of the present invention, the at least one binder is an anionic polymer binder. Examples of suitable anionic polymeric binders include carboxylate containing polymers such as olefinically unsaturated carboxylic acids such as monocarboxylic acids (e.g., acrylic acid and / or methacrylic acid) or such as dicarboxylic acids (e.g., Maleic acid or maleic anhydride and / or fumaric acid and / or itaconic acid and / or citraconic acid), or such as tricarboxylic acids (such as aconitic acid) and acrylonitrile, butadiene, monovinylidene aromatic monomers, Such as styrene and styrene derivatives such as alpha-methylstyrene and / or ortho-, meta-, para-methylstyrene, styrene-butadiene, olefinically unsaturated esters such as acrylic acid and / or methacrylic acid alkyl esters, Butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, butyl methacrylate), and mixtures thereof. Examples of suitable polymeric binders include poly (styrene-co-butadiene), polyurethane latex, polyester latex, poly (n-butyl acrylate), poly (n-butyl methacrylate) A copolymer of n-butyl acrylate and ethyl acrylate, or a copolymer of vinyl acetate and n-butyl acrylate.

According to a preferred embodiment of the present invention, the at least one binder is selected from the group consisting of ethylene methyl acrylate, homopolymers and / or copolymers of ethylene acrylic acid, polyacetates, polybutylenes, polybutyleneterephthalates, polyphthalate carbonates, But are not limited to, acrylic acid, methacrylic acid, maleic anhydride, maleic anhydride, phthalate, polylactic acid, styrene acrylonitrile, acrylonitrile styrene acrylate, polyethersulfone, polystyrene, polyethylene, high density polyethylene, polypropylene, ethylene vinyl acetate, nylon, Acrylonitrile butadiene styrene, polyoxymethylene, polyoxymethyl methacrylate, or a mixture thereof. The term " thermoplastic polymer " The homopolymers and / or copolymers may be cross-linkable or non-cross-linkable. According to one exemplary embodiment, the at least one binder is selected from the group consisting of comonomers of C ₃ -C ₁₂ - α-olefins, preferably butyne-1-enes, hex-1-enes, 4-methyl- , Hept-1-ene, oct-1-ene, and de-1-ene, more preferably selected from the group consisting of but-1-ene and hex-1-ene .

According to a preferred embodiment, the at least one binder is selected from the group comprising styrene-acrylate-copolymers and styrene-butadiene-copolymers, and mixtures thereof.

According to one embodiment of the invention, the solution or emulsion or dispersion of the one or more binders is an aqueous solution or emulsion or dispersion, i.e. the solvent used to make the solution or emulsion or dispersion is water.

According to a preferred embodiment of the present invention, the one or more binders are provided in the form of an aqueous dispersion. When the binder is provided in the form of a dispersion, the particle size of the binder may have a d ₅₀ value of from 10 to 800 nm, preferably from 20 to 500 nm, more preferably from 25 to 100 nm. However, the one or more binders may also be provided in the form of a solution or emulsion or in the form of a solution and / or a mixture of emulsions and / or dispersions.

According to one embodiment of the present invention, the amount of the at least one binder is less than 10% by weight, preferably less than 7% by weight, more preferably less than 5% by weight, most preferably less than 10% by weight based on the total weight of the calcium carbonate- Preferably 0.1 to 4% by weight.

According to one embodiment of the invention, one or more solutions or emulsions or dispersions of the one or more binders of step (b) comprise 10 to 70 wt% binder, preferably 40 to 80 wt%, based on the total weight of the solution or emulsion or dispersion, 65% by weight of the binder, more preferably 45 to 55% by weight of the binder.

According to one embodiment of the invention, the amount of at least one solution or emulsion or dispersion of one or more of the binders of step (b) is less than 10% by weight, preferably less than 7% by weight, based on the total weight of the calcium carbonate- , More preferably less than 5 wt%, and most preferably 0.1 to 4 wt%.

Process step (c): Step of contacting the calcium carbonate-containing mineral powder with the binder

In process step (c), the one or more calcium carbonate-containing mineral powders of step (a) are brought into contact with one or more solutions or emulsions or dispersions of the binder of step (b) in an amount to form solid calcium carbonate-containing multiparticulates.

The one or more solutions or emulsions or dispersions of the binder of step (b), and optionally further components, are added in an amount to form solid calcium carbonate-containing multiparticulates. The solution or emulsion or dispersion of the binder of step (b), and optionally further components, can be obtained by adding to the calcium carbonate-containing mineral powder a solid product, i. E. A product having a final solids content of at least 90 wt.%, Based on the total weight of the product It should be noted that the amount added is ensured. In other words, the formation of the liquid reaction mixture by variously adding a solution or emulsion or dispersion of the binder of step (b), and optionally further components, should be avoided, if necessary, by heat and / or vacuum.

The step of contacting one or more calcium carbonate-containing mineral powders with one or more solutions or emulsions or dispersions of the binder of step (b) may be carried out under mixing and / or homogenization conditions. Those skilled in the art will be able to suitably adjust such mixing and / or homogenization conditions, such as mixing speed and temperature according to their processing equipment.

For example, mixing and homogenization can occur by means of a plowshare mixer. The flusher type mixer operates by the principle of a mechanically generated fluidized layer. The flusher-type blade rotates close to the inner wall of the horizontal cylindrical drum to transfer the components of the mixture from the product layer into the development mixing space. The mechanically generated fluidized layer ensures strong mixing of much larger batches in a very short time. Choppers and / or dispersers are used to disperse the agglomerates by a drying operation. Equipment that can be used in the process of the present invention is, for example, available from Gebrueder Loedige Maschinenbau GmbH, Germany.

According to one embodiment of the present invention, process step (c) is carried out using a fluidized bed mixer or a flusher type mixer.

According to one embodiment of the invention, process step (c) recirculates the aggregates and / or agglomerates formed in the grinding apparatus, preferably in a ball mill, preferably during process step (c), back to the inlet of the grinding apparatus It is implemented in combination with a cyclone device. It makes it possible to separate particulate matter, such as particles, aggregates or aggregates, into fractions of smaller particulate matter and fractions of larger particulate matter on the basis of gravity.

According to an exemplary embodiment, the calcium carbonate-containing composite particles formed during process step (c) are divided into smaller particles. The term "split" as used in the present invention means that the particles are divided into smaller particles. This may be done by milling, such as milling, such as ball mills, hammer mills, rod mills, vibratory mills, roll crushers, centrifugal impact mills, vertical bead mills, attrition mills, pin mills, hammer mills, mills, crushers, decurling machines, And may be carried out by pulverization. However, any other device capable of dividing calcium carbonate-containing multiparticulates formed during process step (c) into smaller particles can be used.

Process step (c) can be carried out at room temperature, i. E. 20 C or at another temperature. According to one embodiment, process step (c) is carried out at a temperature of from 5 to 140 캜, preferably from 10 to 110 캜, most preferably from 20 to 105 캜. Without wishing to be bound by any theory, adhesion of the binder to the surface of the calcium carbonate-containing mineral powder can be improved by performing the process step (c) at a temperature above room temperature, for example, at a temperature of 40 to 105 ° C. The heat may be introduced by internal shear or by an external source or by a combination thereof.

According to an exemplary embodiment of the invention, the at least one calcium carbonate-containing mineral powder is preheated before it is contacted with at least one solution or emulsion or dispersion of the binder of step (b). For example, the calcium carbonate-containing mineral powder may be preheated at a temperature of 30 to 100 占 폚, 40 to 90 占 폚, or preferably 50 to 80 占 폚.

According to one embodiment of the invention, process step (c) is carried out for more than 1 s, preferably for more than one minute, for example 15 minutes, 30 minutes, 1 hour, 2 hours, 4 hours, 6 hours, 8 Hour or more than 10 hours.

According to one embodiment of the present invention, process step (c) is carried out at 20 DEG C for at least 30 minutes. According to another exemplary embodiment, process step (c) is carried out at 80 DEG C for at least 30 minutes.

According to another exemplary embodiment of the present invention, process step (c) is carried out in a rotor-stator mixer at a temperature of 80 to 150 캜, preferably at a temperature of 120 캜 for 1 to 10 s, for example 2 For 3 s, at an industrial production rate of the composite particles of 2 to 5 tons per hour.

According to another exemplary embodiment of the present invention, the process step (c) is divided into a treatment step and a heating step, wherein the treatment step comprises mixing at least one calcium carbonate-containing mineral powder of step (a) With one or more solutions or emulsions or dispersions. For example, the treatment step and the heating step may be performed together, or the treatment step and then the heating step may be performed.

According to one exemplary embodiment of the invention, the homogenization step is carried out after one or more calcium carbonate-containing mineral powders are contacted with one or more solutions or emulsions or dispersions of one or more binders of step (b).

To ensure a better dispersion, a dispersant may also be added to any of the components used in the process of the present invention, for example in the form of an aqueous solution and / or powder of a dispersant. Suitable dispersing agents are selected from the group comprising homopolymers or copolymers of polycarboxylic acid salts such as polycarboxylic acid salts based on acrylic acid, methacrylic acid, maleic acid, fumaric acid or itaconic acid and acrylamide or mixtures thereof . Particularly preferred are homopolymers or copolymers of acrylic acid. The weight average molecular weight M _w of such a product is preferably in the range of 2000 to 15000 g / mol, and the weight average molecular weight M _w is particularly preferably in the range of 3000 to 7000 g / mol or 3500 to 6000 g / mol. In accordance with the illustrative embodiments, the dispersing agent is sodium polyacrylate having a weight average molecular weight M _w of 2000 to 15000 g / mol, preferably 3000 to 7000 g / mol, and most preferably from 3500 to 6000 g / mol.

The obtained solid calcium carbonate-containing composite particles

According to one embodiment of the present invention, the solid content of the obtained solid calcium carbonate-containing composite particles is at least 90% by weight, for example at least 95% by weight, preferably at least 99% by weight , Preferably at least 99.5 wt%, or most preferably at least 99.8 wt%, or even > 99.9 wt%.

According to an optional embodiment, the process of the present invention comprises an additional process step (d) wherein the calcium carbonate-containing composite particles obtained in step (c) are dried.

The calcium carbonate-containing composite particles can be dried, for example, thermally, for example, by a spray dryer or microwave or in an oven, or mechanically, for example by filtration or by lowering the moisture content have.

According to certain embodiments of the present invention, the calcium carbonate-containing composite particles are dried in an oven at a temperature of from 50 to 150 캜, preferably from 80 to 120 캜, more preferably about 110 캜.

According to another optional embodiment of the present invention, the resultant calcium carbonate-containing composite particles are dispersed in a water atmosphere having a relative humidity of preferably 50%, based on the total weight of the composite particles, after 48 hours at 23 DEG C , Less than 1 wt.%, Less than 0.8 wt.%, Less than 0.5 wt.%, Preferably less than 0.2 wt.%, Most preferably less than 0.1 wt.%.

The dried calcium carbonate-containing multiparticulates at a total surface moisture content of less than 0.5% by weight, based on the total weight of the multiparticulates, is increased in equivalent or improved fluidity compared to the calcium carbonate containing mineral powder provided in step (a) Lt; / RTI > bulk density.

According to one embodiment of the present invention, the bulk density of the dried calcium carbonate-containing multiparticulates is such that, at a total surface moisture content of less than 0.5% by weight based on the total weight of the multiparticulates, the calcium carbonate-containing minerals Is increased by 5 to 80%, preferably by 8 to 60%, more preferably by 10 to 50% as compared with the powder. The bulk density of the dried calcium carbonate-containing composite particles may be, for example, 0.5 to 1.0 kg / dm ³ , 0.6 to 0.9 kg / dm ³ , or 0.7 to 0.8 kg / dm ³ .

According to another embodiment of the present invention, the energy consumption required to move the dried calcium carbonate-containing multiparticulates at a total surface moisture content of less than 0.5% by weight, based on the total weight of the multiparticulates, Containing calcium carbonate-containing mineral powder.

According to an exemplary embodiment of the invention, the energy consumption of the dried calcium carbonate-containing multiparticulates at a total surface moisture content of less than 0.5% by weight, based on the total weight of the multiparticulates, is greater than the calcium carbonate-containing minerals Is reduced by 0 to 40%, preferably by 5 to 30%, more preferably by 10 to 20% as compared with the powder. The energy consumption of the dried calcium carbonate-containing composite particles may be, for example, 1 to 20 kJ / t, 4 to 16 kJ / t, or 6 to 14 kJ / t.

The dried calcium carbonate-containing composite particles of the present invention can be used in paper applications, in paints or in plastics.

Optional process steps: one or more calcium carbonate-containing mineral powders and one or more Cationic  Step of contacting with polymer

According to a further optional embodiment of the invention, the at least one calcium carbonate-containing mineral powder provided in step (a) is contacted with one or more solutions or emulsions or dispersions of one or more cationic polymers before, during or after step (c) . Without wishing to be bound by any theory, it is believed that the cationic polymer is capable of improving the adhesion of the one-way binder to the calcium carbonate-containing mineral powder.

According to one embodiment of the present invention, the at least one cationic polymer comprises at least one dicarboxylic acid as the monomer and at least one monomer selected from the group of diamines, triamines, dialkanolamines or trialkanolamines and epichlorohydrin, ≪ / RTI >

Dicarboxylic acid monomer include preferably saturated or unsaturated, branched or unbranched C ₂ -C _{10 - -} acid, in particular C ₃ -C ₉ - dicarboxylic acids, C ₄ -C ₈ - dicarboxylic C ₅ -C ₇ -dicarboxylic acids, especially adipic acid, are used.

As the second monomer of the binder polymer, linear or branched, substituted and unsubstituted diamines and triamines, especially N- (2-aminoethyl) -1,2-ethane-diamine, are particularly suitable.

Preferred dialkanolamines and trialkanolamines include, for example, diethanolamine, N-alkyldialkanolamines such as N-methyl- and N-ethyl-diethanolamine and triethanolamine.

In order to monitor and control the molecular weight and / or chain length of the copolymer, one or more monovalent amines such as monoalkanolamine may be used during polycondensation. According to a preferred embodiment, monoethanolamine is used.

According to a preferred embodiment of the present invention, the resulting intermediate copolymer is then reacted with epichlorohydrin. According to another preferred embodiment, the resulting intermediate copolymer has a weight of from 800 to 1200 g / mol, preferably from 900 to 1100 g / mol or from 950 to 1050 g / mol, before it reacts with epichlorohydrin And has an average molecular weight M _w .

According to another embodiment of the present invention, the at least one cationic polymer is a polyethyleneimine (PEI) selected from the group comprising branched polyethyleneimines, linear polyethyleneimines and mixtures thereof. Preferably, the primary, secondary and tertiary amine functionalities in the branched polyethyleneimines of the present invention are in the range of 1: 0.86: 0.42 to 1: 1.20: 0.76 before possible modification of the branched polyethyleneimine.

According to one preferred embodiment of the present invention, the one or more polyethylene imines are selected from the group of modified and unmodified polyethyleneimines.

Examples of suitable polyethyleneimines are homopolymers of ethyleneimine (aziridine) or higher homologues thereof and also graft polymers of polyimidoamines or polyvinylamines with ethyleneimine or its higher homologues. The polyethyleneimine can be cross-linked or non-crosslinked, quarternized and / or modified by reaction with an alkylene oxide, a dialkyl or alkylene carbonate or a C ₁ -C ₈ -carboxylic acid. Polyethylene imines include alkylene oxides such as ethylene oxide, propylene oxide or butylene oxide, dialkyl carbonates such as dimethyl carbonate and diethylene carbonate, alkylene carbonates such as ethylene carbonate or propylene carbonate Borate, or C ₁ -C ₈ -carboxylic acid. The modified PEI may comprise alkoxylated polyethyleneimines such as propoxylated polyethyleneimine (PPEI) and ethoxylated polyethyleneimine (EPEI). Further preferred modified polyethyleneimines include unmodified PEI with one or more C ₁ -C ₂₈ -fatty acids, preferably one or more C ₆ -C ₁₈ -fatty acids, particularly preferably C ₁₀ -C ₁₄ -fatty acids, For example, coconut fatty acid or the like. One method of preparing PEI-containing cationic polymers is based on the reaction of ethylenediamine (EDA) with ethyleneimine (EI) under acid catalysis in a solvent such as water. An example of a common ethyleneimine is aziridine. The resulting polyethyleneimine (PEI) in the composition has primary, secondary and tertiary amine functionalities available for the reaction to form APEI by alkoxylation with an additional chemical conversion reaction, such as an alkylene oxide such as ethylene oxide. PEI can also be prepared from diamines or polyamines such as ethylenediamine (EDA), ethyleneimine (EI) such as aziridine, water and acid catalysts.

According to a preferred embodiment of the present invention, the at least one cationic polymer is a modified polyethyleneimine, preferably modified by a carboxylic acid group, more preferably one or more C ₁ -C ₂₈ -fatty acids, one or more C ₆ -C ₁₈ - fatty acids or one or more C ₁₀ -C ₁₄ - will be modified by fatty acids, or alkoxylated, preferably modified by ethoxylation, ethoxylated using an more preferably 10 to 50 ethylene oxide .

In a preferred embodiment of the invention, the polyethyleneimine has a weight average molecular weight M _w in the range from 100 g / mol to 10000 g / mol. In another preferred chamber embodiments of the present invention, polyethyleneimine is from 100 to 700 g / mol and preferably is selected from a linear polyethyleneimine having a weight-average molecular weight M _w of 146 to 232 g / mol group, preferably a Triethylene tetramine, pentaethylene hexamine, and tetraethylene pentamine. According to a further preferred embodiment, the polyethyleneimine is selected from 500 to 8000 g / mol, preferably 800 to 1200 g / mol average molecular weight minutes group of branched polyethyleneimine having a M _w of.

According to one exemplary embodiment of the present invention, at least one cationic polymer is a copolymer of adipic acid and N- (2-aminoethyl) -1,2-ethanediamine and epichlorohydrin. According to a preferred embodiment of the present invention, the at least one cationic polymer is selected from linear polyethyleneimines, polyamine amide epichlorohydrin, or mixtures thereof.

As the at least one cationic polymer, it is preferable to use polyamine amide epichlorohydrin.

According to a preferred embodiment of the present invention, the at least one calcium carbonate-containing mineral powder provided in step (a) is contacted with one or more solutions or emulsions or dispersions of the cationic polymer before, during or after step (c) The binder is an anionic binder. Without wishing to be bound by any theory, it is believed that the combination of the cationic polymer and the anionic binder can further improve the adhesion of one or more binders on the calcium carbonate-containing mineral powder.

According to one embodiment of the present invention, the amount of the at least one cationic polymer used in the process of the present invention is less than 1.0% by weight, preferably less than 0.8% by weight, more preferably less than 0.1% by weight based on the total weight of the calcium carbonate- Is less than 0.5% by weight, most preferably less than 0.2% by weight.

According to one embodiment of the present invention, the one or more cationic polymers are provided in aqueous form, for example in the form of aqueous solutions or emulsions or dispersions.

When one or more polymers are provided in the form of a dispersion, the particle size of the cationic polymer may have a d ₅₀ value of 10 to 500 nm, preferably 20 to 100 nm, more preferably 25 to 80 nm.

According to one embodiment of the invention, one or more solutions or emulsions or dispersions of the cationic polymer are present in an amount of from 5 to 70% by weight, preferably from 10 to 50% by weight, more preferably from 5 to 70% by weight, based on the total weight of the solution or emulsion or dispersion By weight of at least one cationic polymer.

According to a preferred embodiment of the present invention, the at least one cationic polymer is present in an aqueous solution, preferably 10 to 50% by weight, more preferably 11 to 30% by weight, most preferably 12 To 17% by weight of at least one cationic polymer.

However, the at least one cationic polymer may also be provided in the form of an emulsion or dispersion, or in the form of a solution and / or a mixture of emulsions and / or dispersions.

According to one embodiment of the present invention, the amount of at least one solution or emulsion or dispersion of at least one cationic polymer used in the process of the present invention is less than 1.0% by weight, preferably less than 1.0% by weight, based on the total weight of the calcium carbonate- Less than 0.8% by weight, more preferably less than 0.5% by weight, most preferably less than 0.2% by weight.

The contacting step of one or more calcium carbonate-containing mineral powders with one or more solutions or emulsions or dispersions of the cationic polymer may be carried out under mixing and / or homogenization conditions. The mixing and / or homogenization conditions may be the same as those described above for process step (c).

According to one embodiment, the one or more calcium carbonate containing mineral powders are preheated before it is contacted with one or more solutions or emulsions or dispersions of the cationic polymer.

According to one embodiment of the present invention, one or more calcium carbonate-containing mineral powders are brought into contact with at least one solution or emulsion or dispersion of one or more cationic polymers prior to process step (c). According to another embodiment of the present invention, one or more calcium carbonate containing mineral powders are brought into contact with at least one solution or emulsion or dispersion of one or more cationic polymers during process step (c). According to another embodiment of the present invention, one or more calcium carbonate-containing mineral powders are brought into contact with at least one solution or emulsion or dispersion of one or more cationic polymers after process step (c). Preferably, the at least one calcium carbonate-containing mineral powder is brought into contact with at least one solution or emulsion or dispersion of one or more cationic polymers prior to process step (c).

According to one exemplary embodiment of the invention, the homogenization step is carried out after one or more calcium carbonate-containing mineral powders are contacted with at least one solution or emulsion or dispersion of cationic polymer and after at least one solution or emulsion of the binder of step (b) Or before contact with the dispersion. According to another exemplary embodiment of the invention, the homogenization step is carried out after one or more calcium carbonate containing mineral powders are contacted with one or more solutions or emulsions or dispersions of the binder of step (b) and after one or more solutions or emulsions of the cationic polymer Emulsion or dispersion.

Additional optional process steps

According to a further optional embodiment, the present invention comprises an additional process step (e) wherein the dried calcium carbonate-containing composite particles are sorted and / or air sorted to remove undesirable large particles. The screening can be carried out using screening equipment, for example, circle-through vibration screening equipment, high-frequency vibration equipment or pivoting equipment. Air classification can be performed using an air separator that operates by injecting the material stream to be separated and separated in a combination of size, shape, and density into a chamber that holds a column of rising air. Due to the dependence of the air drag on the object size and formation, the material particles in the moving air column can be vertically separated and separated in this way.

According to one embodiment of the present invention, particles greater than 100 microns, preferably greater than 50 microns, and more preferably greater than 20 microns, are removed. Preferably, the undesirable large particles are contained in the obtained dried calcium carbonate-containing composite particles in an amount of not more than 1000 ppm, more preferably not more than 100 ppm, for example, 50 to 80 ppm or 60 to 70 ppm .

According to another optional embodiment, a slurry is prepared by adding water from the calcium carbonate-containing composite particles obtained by step (c).

Optionally, a dispersant may be used to prepare the slurry. The dispersant may be used in an amount of from 0.01 to 10% by weight, from 0.05 to 8% by weight, from 0.5 to 5% by weight, from 0.8 to 3% by weight, or from 1.0 to 1.5% by weight, based on the total weight of the calcium carbonate- . In a preferred embodiment, the pigment is dispersed in an amount of 0.05 to 5% by weight, preferably 0.5 to 5% by weight, based on the total weight of the composite particles. Suitable dispersing agents include homopolymers or copolymers of polycarboxylic acid salts such as polycarboxylic acid salts based on acrylic acid, methacrylic acid, maleic acid, fumaric acid or itaconic acid and acrylamide or mixtures thereof . ≪ / RTI > Particularly preferred are homopolymers or copolymers of acrylic acid. The weight average molecular weight M _w of such a product is preferably in the range of 2000 to 15000 g / mol, and the weight average molecular weight M _w is particularly preferably 3000 to 7000 g / mol or 3500 to 6000 g / mol. In accordance with the illustrative embodiments, the dispersing agent is sodium polyacrylate having a 2000 to 15000 g / mol, preferably 3000 to 7000 g / mol, and most preferably a weight-average molecular weight M _W of 3500 to 6000 g / mol.

The slurry prepared from the calcium carbonate-containing multiparticulates is preferably present in an amount of from 10 to 82% by weight, preferably from 50 to 81% by weight, more preferably from 60 to 70% by weight or from 70 to 78% by weight, based on the total weight of the slurry, Can have a content.

Example

The following examples illustrate different calcium carbonate containing composite particles prepared according to the process of the present invention.

A. matter

Calcium carbonate-containing mineral powder:

Calcium carbonate 1: 25% by weight, based on the total weight of the slurry, wet milled and spray dried Carrara marble, particle size ( d ₅₀ ): 1.8 μm.

Calcium carbonate 2: Dry marble, marble from the Carrara region of Italy, particle size ( d ₅₀ ): 3.4 μm.

Calcium carbonate 3: Dry marble, marble, dry granulated, Carrara region, particle size ( d ₅₀ ): 5.3 μm.

Calcium carbonate 4: dry milled Austrian Villach marble, particle size ( d ₅₀ ): 2.6 탆.

Calcium carbonate 5: dry crushed Danish region acid chalk, particle size (d ₅₀ ): 2.4 탆.

Cationic polymer :

Cationic polymer 1: linear polyethyleneimine, concentration > 99%

Cationic polymer 2: Polyamine amide dissolved in water Epichlorohydrin, concentration: 15% by weight, based on the total weight of the solution.

Binder:

Binder 1: Styrene-acrylate copolymer dispersed in water, concentration: 50% by weight, based on the total weight of the dispersion.

Binder 2: Styrene-butadiene copolymer dispersed in water, concentration: 50% by weight, based on the total weight of the dispersion.

Dispersant 1: sodium polyacrylate, M _w = 3500 g / mol

B. Method:

 Treatment process 1

3000 g of CaCO ₃ powder was placed in a Loedige mixer (Gebrueder Loedige Maschinenbau GmbH, Germany), and the mixer was run while a cationic polymer solution was added. After a 5 minute homogenization step, a binder dispersion was added and the mixture was homogenized for an additional 30 minutes. If a cationic polymer was not used, the binder dispersion was initially loaded instead of the cationic polymer.

The obtained product was tempered in a drying oven at 110 DEG C for 15 hours.

Treatment process 2

A CaCO ₃ powder of 3000 g in a dry oven of 80 ℃ was preheated for 2 hours. The CaCO _{3 was} then placed in a Loedige mixer (Gebrueder Loedige Maschinenbau GmbH, Germany), preheated to 80 ° C and the cationic polymer solution added while the mixer was running. After 5 minutes of homogenization, the binder dispersion was added and the mixture was homogenized for an additional 30 minutes. During the entire treatment process, the Loedige mixer temperature was maintained at 80 占 폚. The cationic polymer and binder were not pre-heated. If no cationic polymer was added, the binder dispersion was added initially in place of the cationic polymer.

The obtained product was tempered in a drying oven at 110 DEG C for 15 hours.

Treatment process 3

500 g of CaCO ₃ powder was placed in a mixer type M3 / 1.5 (MTI Mischtechnik International GmbH, Germany) and the mixing was operated at 500 rpm. The cationic polymer solution and the binder dispersion were then introduced into the CaCO ₃ powder at room temperature. The contents of the mixer were mixed at a stirring speed of 500 rpm for 10 or 20 minutes.

The obtained product was tempered in a drying oven at 110 DEG C for 15 hours.

Conditioned Bulk Density ( CBD : conditioned bulk density )

Conditioned bulk density was measured with a Powder Rheometer System FT4 (Freeman Technology Ltd., UK) which conditions the powder to achieve a uniform charge state of low stress.

The conditioning process entailed a light batch of the entire sample to loosen the powder and allow a little air to form a uniformly packed powder bed. The conditioning cycle included the downward traversal of the blade followed by the upward traversal. The downward traversal uses a 5 ° positive helix to slice the blade action rather than compacting it. An upward traverse was used with a 5 ° negative woof angle to gently raise the powder gently and allow the powder to fall onto the blade, leaving each particle thereafter. After the conditioning cycle, the powder sample did not contain the unionized stress and any excess air.

Samples corresponding to a volume of 160 ml were then weighed using an internal balance of the Powder Rheometer System FT4, and the conditioned bulk density was automatically calculated with the flow meter.

Measurement of energy consumption for powder transport

The energy required to transport one thousand metric tons of powder was measured using a Powder Rheometer System FT4 (Freeman Technology Ltd., UK) and the specific order of stability (Rep) and the variable flow rate (VFR) test sequence Was provided by the Powder Rheometer System FT4.

The configuration of the Rep + VFR test was a combination of the seven conditioning and test cycles of the stability test and the four conditioning and test cycles of the variable flow test as illustrated below.

Where splitting of the vessel to provide a precise volume of powder in the C = conditioning cycle, T = test cycle, (x) = blade tip speed (mm / s), and split = . Powder mass was automatically recalculated after splitting. The blade tip speed was 100 m / s, which was not defined in parentheses (during the Rep order).

Brookfield  Measurement of viscosity

Brookfield viscosity was measured at 23 [deg.] C using a Brookfield DVII + viscometer at 100 rpm.

Measurement of particle size

For the measurement of the weight of the center grain size d ₅₀ it was used as a Sedigraph 5100 device (US company, Micromeritics). This measurement was performed in an aqueous solution of 0.1 wt% Na ₄ P ₂ O ₇ . The samples were dispersed using a high-speed stirrer and ultrasonic waves.

Measurement of total surface moisture content

The total surface moisture content was measured according to a Coulometric Karl Fischer measurement method, wherein the dried calcium carbonate composite particles were heated to 220 ° C and discharged as a vapor using a stream of nitrogen gas (100 ml / min) The content was measured in a Coulometric Karl Fischer unit.

C. Results

Example  One

2000 g of calcium carbonate 1 is treated using Treatment 2, wherein 0.5% by weight of cationic polymer 1 and 8% by weight of Binder 2 are added, wherein the% by weight is based on the total weight of calcium carbonate .

The products of the present invention exhibited higher bulk density and lower energy needed to transfer the product compared to untreated calcium carbonate (Table 1).

Furtherance Bulk density
(kg / dm ³ ) Energy consumption
(kJ / t) preceding
Technology 99.8 wt% calcium carbonate 1
0.2% by weight of water 0.50 14.2 Invention 91.3% by weight calcium carbonate 1
0.5% by weight of cationic polymer 1
8.0% by weight of binder 2
0.2% by weight of water 0.80
(+ 60%) 12.2
(- 14.1%)

Example  2

2000 g of calcium carbonate 2 is surface treated using Treatment Step 1 wherein 0.2 wt% of cationic polymer 2 and 3 wt% of Binder 1 are added, wherein the wt% is based on the total weight of calcium carbonate will be.

The products of the present invention exhibited higher bulk density and lower energy needed to transfer the product compared to untreated calcium carbonate (Table 2).

Furtherance Bulk density
(kg / dm ³ ) Energy consumption (kJ / t) preceding
Technology 99.8% by weight calcium carbonate 2
0.2% by weight of water 0.76 7.0 Invention 96.6% by weight calcium carbonate 2
0.2% by weight of cationic polymer 2
3.0 wt% binder 1
0.2% by weight of water 0.82
(+ 7.9%) 4.6
(- 34.4%)

Example  3

Product A:

3000 g of calcium carbonate 3 is surface treated using Treatment Step 1 wherein 0.2 wt% of cationic polymer 2 and 3 wt% of Binder 1 are added, wherein the wt% is based on the total weight of calcium carbonate will be.

Product B:

500 g of calcium carbonate 3 is surface treated using Treatment 3, wherein 3 wt% of Binder 1 is used, wherein the wt% is based on the total weight of calcium carbonate.

The products of the present invention exhibited higher bulk density and lower energy needed to transfer the product compared to untreated calcium carbonate (Table 3).

Furtherance Bulk density
(kg / dm ³ ) Energy consumption
(kJ / t) preceding
Technology 99.8% by weight calcium carbonate 3
0.2% by weight of water 0.85 5.6 The product A 96.6% by weight calcium carbonate 3
0.2% by weight of cationic polymer 2
3.0 wt% binder 1
0.2% by weight of water 0.92
(+ 8.2%) 4.9
(- 12.5%) Invention
Product B 96.6% by weight calcium carbonate 3
3.0 wt% binder 1
0.2% by weight of water 0.94
(+ 10.6%) 3.6
(- 35.7%)

Example  4

3000 g of calcium carbonate 5 are surface treated using Treatment Step 1 wherein 0.2 wt% of cationic polymer 2 and 3 wt% of Binder 1 are added, wherein the wt% is based on the total weight of calcium carbonate It is.

The product of the present invention exhibited higher bulk density and lower energy needed to transfer the product as compared to untreated calcium carbonate (Table 4).

Furtherance Bulk density
(kg / dm ³ ) Energy consumption
(kJ / t) preceding
Technology 99.6 wt% calcium carbonate 5
0.4% by weight of water 0.46 13.9 Invention 96.4 wt% calcium carbonate 5
0.2% by weight of cationic polymer 2
3.0 wt% binder 1
0.4% by weight of water 0.62
(+ 34.8%) 10.9
(- 21.6%)

Example  5

Product C:

2000 g of calcium carbonate 4 is surface treated using Treatment 2, wherein 0.2% by weight of cationic polymer 2 and 2% by weight of Binder 1 are added, wherein the weight% is based on the total weight of calcium carbonate It is.

Product D:

2000 g of calcium carbonate 4 is surface treated using Treatment Step 1 wherein 0.2 wt% of cationic polymer 1 and 2 wt% of Binder 1 are added, wherein the wt% is based on the total weight of calcium carbonate It is.

Product E:

2000 g of calcium carbonate 4 is surface treated using Treatment Step 1 wherein 0.2 wt% of cationic polymer 2 and 5 wt% of Binder 1 are added, wherein the wt% is based on the total weight of calcium carbonate It is.

The products of the present invention exhibited higher bulk density and similar or lower energy needed to transfer the product compared to untreated calcium carbonate (Table 5)

Furtherance Bulk density
(kg / dm ³ ) Energy consumption
(kJ / ton) preceding
Technology 99.8 wt% calcium carbonate 4
0.3% by weight of water 0.72 6.4 The product C 97.5% by weight calcium carbonate 4
0.2% by weight of cationic polymer 2
2.0 wt% binder 1
0.3% by weight of water 0.79
(+ 9.7%) 6.4
(- 0%) The product D of the present invention 97.5% by weight calcium carbonate 4
0.2% by weight of cationic polymer 1
2.0 wt% binder 1
0.3% by weight of water 0.78
(+ 8.3%) 5.4
(-15.6%) The product E of the present invention 94.5% by weight calcium carbonate 4
0.2% by weight of cationic polymer 2
5.0 wt% binder 1
0.3% by weight of water 0.90
(+ 25.0%) 6.0
(- 6.3%)

Example  6

A slurry having 65 wt% solids was prepared using 2000 g of the product of Example 2 and 0.03 wt% of Dispersant 1, wherein the wt% is based on the weight of dry CaCO ₃ .

The Brookfield viscosity of the obtained slurry was 620 mPas.

Example  7

A slurry with 65 wt% solids was prepared using 2000 g of Example 3 product A and 0.03 wt% of Dispersant 1, wherein the wt% is based on the weight of dry CaCO ₃ .

The Brookfield viscosity of the obtained slurry was 510 mPas.

Claims (21)

CLAIMS What is claimed is: 1. A method for preparing a calcium carbonate-containing composite particle comprising the steps of:
(a) providing at least one calcium carbonate-containing mineral powder,
(b) preparing at least one solution or emulsion or dispersion of at least one binder, wherein the at least one binder is selected from the group consisting of copolymers of acrylonitrile, butadiene, acrylate, butyl acrylate, styrene, styrene-butadiene, , And mixtures thereof, wherein the amount of the at least one binder is less than 10% by weight based on the total weight of the calcium carbonate-containing mineral powder,
(c) contacting at least one calcium carbonate-containing mineral powder of step (a) in an amount to form a solid calcium carbonate-containing composite particle with at least one solution or emulsion or dispersion of the binder of step (b)
Wherein the calcium carbonate-containing composite particles obtained in step (c), when dried at a total surface moisture content of less than 0.5% by weight based on the total weight of the composite particles, are 0.5 Has an increased bulk density at equivalent or improved flowability as compared to the calcium carbonate containing mineral powder provided in step (a) when dried to a total surface moisture content of less than about 1 wt%. 2. The method of claim 1, wherein the bulk density of the dried calcium carbonate-containing multiparticulates is compared with the calcium carbonate-containing mineral powder provided in step (a) at a total surface moisture content of less than 0.5 wt% based on the total weight of the multiparticulates By 5 to 80%. 3. The method of claim 1 or 2, wherein the at least one calcium carbonate-containing mineral powder provided in step (a) is selected from the group consisting of GCC and PCC, and mixtures thereof. The process according to any one of claims 1 to 3, wherein the powder particles of the at least one calcium carbonate-containing mineral powder provided in step (a) have a d ₅₀ value of 0.1 to 100 탆. The method of any one of claims 1 to 3, wherein the at least one calcium carbonate-containing mineral powder provided in step (a) has a total surface moisture content of less than 10% by weight based on the total weight of the mineral powder. 3. The method of claim 1 or 2, wherein the at least one binder provided in step (b) is selected from the group comprising styrene-acrylate-copolymer and styrene-butadiene-copolymer, and mixtures thereof. The method of any of the preceding claims, wherein the amount of the at least one binder provided in step (b) is less than 10% by weight based on the total weight of the calcium carbonate-containing mineral powder. 3. The method of claim 1 or 2, wherein the at least one calcium carbonate containing mineral powder provided in step (a) is contacted with at least one solution or emulsion or dispersion of one or more cationic polymers before, during or after step (c) How it is. 9. The process of claim 8, wherein the at least one cationic polymer is selected from linear polyethyleneimines, or polyamine amide epichlorohydrin, or mixtures thereof. 9. The method of claim 8, wherein the amount of the at least one cationic polymer is less than 1.0% by weight based on the total weight of the calcium carbonate-containing mineral powder. 3. The process according to claim 1 or 2, wherein the process step (c) is carried out at a temperature of from 5 DEG C to 140 DEG C. The method of claim 1 or 2, wherein the method comprises an additional step (d) wherein the calcium carbonate-containing multiparticulates obtained in step (c) comprise less than 1% by weight Lt; RTI ID = 0.0 > moisture content. ≪ / RTI > 13. The method of claim 12, wherein the method further comprises the step of (e) wherein the dried calcium carbonate-containing multiparticulates obtained in step (d) are selected and / or removed in order to remove undesirable larger particles, Or air. The method according to any one of claims 1 to 3, wherein the slurry is prepared from the calcium carbonate-containing composite particles obtained in step (c) by adding water and optionally a dispersant. 15. The method of claim 14, wherein the dispersing agent is sodium polyacrylate having a weight average molecular weight M _w of 2000 to 15000 g / mol. 15. The method of claim 14 wherein the slurry has a solids content of 10 to 82 weight percent based on the total weight of the slurry. Method according to any one of the preceding claims, wherein the method step (c) is carried out in a grinding apparatus. 3. A process according to claim 1 or 2, wherein the calcium carbonate-containing composite particles formed during process step (c) are divided into smaller particles. A method for increasing the bulk density of calcium carbonate-containing mineral powders in an equivalent or improved fluidity using a binder, wherein the binder is selected from the group consisting of acrylonitrile, butadiene, acrylate, butyl acrylate, styrene, styrene-butadiene, ≪ / RTI > copolymers, and mixtures thereof. 18. The method of claim 17, wherein the method step (c) is performed in a ball mill. The method of claim 20, wherein the method step (c) is performed in combination with a cyclone apparatus that recirculates agglomerates and / or aggregates formed during the method step (c) back to the inlet of the grinding apparatus .